In early December, the soccer world wondered aloud whether Barcelona was better under Tito Vilanova than it was under Pep Guardiola.

We’ll never know the answer to that question because throat cancer has taken Vilanova from the bench to the hospital.

Villanova resigned from his job as Barcelona’s head coach on Friday, effective immediately. Club officials said Vilanova would not be able to undergo treatment and coach the reigning La Liga (Spanish first division) champion at the same time.

“We are appearing here before you today to give you some news that I would never in my life have wanted to say and to be very, very precise, I am going to read part of it,” Barcelona president Sandro Rosell told a news conference. “After evaluating the results of routine checks this week monitoring Tito Vilanova, the option has arisen of him undergoing treatment for his illness that will make it incompatible for him to continue acting as the Coach of the first team of Barcelona.

“I would ask you for the utmost respect and privacy for Tito Vilanova and his family for what he will have to now go through.

“Life goes on. This is an extremely tough blow, but Barça has overcome blows like this in the past and this will be no exception. We ask you to show understanding and to remember that we are talking about people, not just the club.”

Barcelona starts the 2013-14 season in less than a month, and Friday’s news has thrown its preparations into disarray. Vilanova’s successor will be named in the coming days, but the instability this causes will have negative effects on Barcelona’s short and medium-term future.

Vilanova first fell ill in late 2011 when doctors discovered a tumor on his pituitary gland. At the time, he was Guardiola’s top assistant. Surgery and treatment saw him take a temporary leave, but he returned with a clean bill of health in early spring 2012.

Vilanova’s Barcelona started the campaign at record-breaking pace, earning 55 if a possible 57 points and scoring 64 goals in the first 19 games of the La Liga campaign. Barcelona also topped its UEFA Champions League group.

All signs pointed to another trophy-filled season midway through Vilanova’s first season in charge. But Vilanova’s cancer returned in mid-December, and he was forced to leave the team again in order to undergo more surgery and chemotherapy. He effectively spent four months (mid-December through mid-march) away from the team, and Barcelona’s form dipped as winter gave way to spring. Barca eventually won La Liga by a 15-point margin and tied Real Madrid’s record for points earned in a season (100 set in 2011-12). But elimination from the Copa del Rey (Spanish cup) and Champions League — both at the semifinal stage — cause many to view the 2012-13 campaign as a disappointment.

Friday’s news brings Vilanova’s tenure as Barcelona’s head coach to a heart-wrenching end. The club, particularly the first team, is tightly knit, and Vilanova’s relapse will understandably shock and unsettle the players and staff who have worked with him on a daily basis since 2007. Other than Vilanova and his own family, Friday’s announcement certainly hits the first team hardest.

Vilanova’s battle with throat cancer is nearing the two-year mark. While it’s impossible to quantify what effect his illness has had on Barcelona’s performances and results, it’s reasonable to think they haven’t been as good as they would have otherwise been had Vilanova had a clean bill of health. Seeing a family member, friend or colleague stricken with a life-threatening illness — especially one as young as the 44-year-old Vilanova — adds stress to the lives of those closest to him or her. In a sport where inspiration, endurance and concentration are often the difference between wins, losses and draws (particularly in the knockout rounds of the Champions League), the extra strain and anxiety the players feel certainly weighs on them as time marches on.

Last winter, Vilanova spent 10 weeks in New York City undergoing chemotherapy and radiotherapy. While his top assistant, Jordi Roura, walked the sidelines during games, Vilanova reportedly remained involved in the decision-making process surrounding tactics, transfers and other minutiae this all-consuming job entails. “Managing from afar” is a phrase that has been used to describe the ailing Barcelona coach in the period between January and March 2013.

In light of Vilanova most recent relapse, he and Barcelona bosses decided that such a scenario cannot repeat itself this season. Barcelona will hire a new head coach next week. Like any coach, the new man will bring his own ideas and opinions to the table, and it will take some time for the players to adapt to them (and vice-versa). Unfortunately the start of the season is a few weeks away, and the adaptation period will likely stretch well into the fall.

Barcelona has reached Champions League semifinals a record six-consecutive times. A seventh appearance looked like a safe bet before Friday. So did the idea that Brazilian sensationNeymar would integrate into the Barcelona attack without much trouble. Both are less certain now that Vilanova has stepped down.

For the last decade, Barcelona has been one of, if not the, greatest club sides in history — particularly in the Guardiola and Vilanova era. It has won 16 trophies since 2008, and we can only wonder how many more it would have captured had cancer not hit Vilanova and former defender Eric Abidal.

Reports of Barcelona’s decline were rife in the media after Bayern Munich hammered its Spanish opposition in last season’s Champions League semifinal. Only time will tell what effect Vilanova’s resignation will have on that “decline.” It could stop or reverse Barcelona’s fall to earth, although that is unlikely. It could also speed up the process. We simply don’t know at this point.

What is clear, however, is that the all-conquering Barcelona teams of recent years lost something when throat cancer hit one of its leaders. Vilanova’s battle with the illness took the limits of Barcelona’s potential down from the cosmos and put it somewhere in the skies of Earth.